The parade theme for Shambino 2021 was HumanKIND, with costumes intended to celebrate humankind’s best achievements. We decided that “The Scientific Method” was our costume so Evelyn decorated four lab coats with lovely drawings and illustrations.
I decided that I’d nerd up the kids ones with some programmable LED’s. These were sewn into the hems and driven by an Arduino plus USB battery pack in the breast pocket. I decided that the trigger for a colour change would be the kids jumping in the air, with the LED’s stepping through the colours of the rainbow. Plus pink. LED functions were easy with the help of the FastLED Arduino library. Detecting jumping took a bit of thought but in the end was trivial. The Arduino is connected to a GY-521 breakout board, which has a MPU-6050 gyroscope and three axis accelerometer. The accelerometer is polled at very short intervals and if any of the acceleration values go to zero a jump is detected. This is detection of the point at the top of a jump, where you’re briefly stationary before falling back down. Works a treat, easy to code and it’s not fooled by shaking etc.
The only tricky bit was self-inflicted by me trying to wedge the Arduino, accelerometer and a PP3 battery into a tiny box. I managed it but the soldering was a pain in the backside. The second one just used more generous wire lengths then bundled it up and covered it in heat shrink.
One thing we were careful of when assembling was to split the LED strips at any points where we wanted some flexibility in the coats and join them with lengths of silicone insulated “noodle” wire. This was because the strips can be quite stiff and we wanted to keep the coats nice and flexible so they weren’t annoying to wear.